1. Field of the Invention
This invention relates to an apparatus for replacing tool sets of powder molding press.
2. Description of the Prior Art
As an apparatus for replacing this kind of tool sets (die sets) in the prior art, for example, a system described in the gazette of Jap.Pat.Publn.No.Sho 55-24399 or Jap.Pat.Publn.No. Sho 62-33039 previously submitted by the present applicant or the like is well known.
In case of the apparatus for replacing the former tool sets, supporting boxes for use in fixing the tool sets are arranged at the extreme ends of the oscillating arms, the tool sets in the boxes are pushed into the press using hydraulic cylinders after oscillating the arms up to the frontal position of the main body of the press so as to enable the tool sets to be set in the main body of the press.
Further, in case of the apparatus for replacing the latter tool sets, transporting bogies for the tool sets are arranged along the parallel rails in such a way as they can freely run in a rightward or a leftward direction, the tool sets moved to the frontal end of the main body of the press by the transporting bogies are pushed into the main body of the press along the bolsters and then the tool sets can be installed at the main body of the press.
However, in the powder molding press machining work in recent years, there is provided a method for molding the final product or approximate final product and reducing a secondary machining work as much as possible due to a requirement of reducing the number of steps or a cost-down.
Due to this fact, a size of each of the tool sets is increased and thus a complex movement of the tool sets is controlled with a strong force applied by a hydraulic pressure or the like and as this controlling operation, servo-valves, proportional solenoid valves and digital valves or the like are used.
In this type of apparatus for replacing the tool sets in the prior art, the hydraulic hoses were removed at the coupler part during movement of the tool sets, the tool sets were set in the main body of the press and the hydraulic hoses placed near the main body of the press were connected to the tool sets by an one-touch coupler.
However, in case of the apparatus for replacing the prior art tool sets, the moving distance of the tool sets up to the center of the press was about 3 m to 6 m and further in case of a large-sized press, a large amount of driving fluid in it caused the hydraulic hoses to be elongated and thickened at its diameter, resulting in that the fixing or removing of the hydraulic hoses caused some troubles or interference against the operation and further a certain oil leakage occurred.
In addition, powders of raw material floating in the air or other dusts entered into the pipe passages when the coupler was removed and they caused a poor operation of the solenoid valves or other components.
In view of the foregoing, it is an object of the present invention to provide an apparatus for replacing the tool sets which does not require any fitting or removal of the fluid pressure pipes such as hydraulic hoses or the like when the tool sets are fitted to or removed from the main body of the press in order to resolve the aforesaid problems of the prior art.
It is also an object of the present invention to provide an apparatus for performing a smooth and easy fitting or removal of the tool sets to and way from the main body of the press.
It is also an object of the present invention to provide an apparatus for replacing the tool sets in which-an oil leakage from the hydraulic hoses is effectively prevented.
It is a still further object of the present invention to provide an apparatus for replacing the tool sets in which the dusts are effectively prevented from entering into the pipe passages.
It is also an object of the present invention to provide an apparatus for replacing the tool sets of which operation is positively carried out.
Other objects and advantages of the present invention will become apparent from the following descriptions concerning the preferred embodiments in reference to the accompanying drawings.